CEREBRO-SPINAL FLUID 155 



nutrition maintained, as, for example, along the paths of 

 the great systemic circulations into the cavities, great and 

 small, where the serous and lymphoid fluids repose, or are 

 stored ; and, out of these, into the organs and channels 

 of excretion, where the final processes of chemical 

 and physiological change are undergone, and the vitally 

 exhausted residual products finally evacuated as absolutely 

 effete and adynamic. 



The inter- and intra-structural cavities and channels thus 

 occupied render great mechanical services in the obviation 

 of structural and inter-structural voids, the bolstering of 

 actively functional textures, and the ballooning of collapsible 

 tissue elements, while at the same time affording nutri- 

 tional facilities for the circulation and interchange of 

 chemic'O-physiological elements in the processes of repair 

 and decay. The spaces and inter-spaces thus occupied 

 vary in size from the atomic and the cellular to that of the 

 largest anatomical cavity, and represent the great and 

 small fluid areas surrounding the histological elements of 

 the entire body ; and, therefore, it becomes necessary to 

 recognise the great physiological fact, that there is no 

 essential material difference in the chemical and physical 

 character of the occupying fluids, save in the added or 

 subtracted amounts of integrative and disintegrative 

 materials respectively, and that thus there is, and can be, 

 but one foundation fluid, the lymph, occupying the entire 

 system and effecting all the changes concerned in the 

 phenomena of its organic, or vegetative, life. 



In thus viewing the subject of the omnipresence of a 

 fundamentally identical fluid element throughout the 

 body from which the nutritional elements are extracted, 

 and into which are returned in a physiologically secured 

 manner, for final disposal, the waste products of functional 

 activity, we must regard its chemical and physiological 

 varieties as due to the textural and visceral contributions, 

 for special physiological purposes and chemical desiderata 

 within the great vital laboratory constituting the living 

 and acting body, and subserving the purposes of its vital 

 chemistry. Consequently, the acts of alimentary absorption, 

 sanguineous circulation, nutrition, lymph circulation and 

 excretion, but illustrate the existence of varieties of this 



